preparation-cell-extracts-cryogrinding-an-automated-freezer

Preparation of Cell Extracts by Cryogrinding in an Automated Freezer Mill

The ease of genetic manipulation and the strong evolutionary conservation of eukaryotic cellular machinery in the budding yeast Saccharomyces cerevisiae ...

Florida State University College of Medicine

Proliferating cells need to synthesize large amounts of histones to rapidly package nascent DNA into nucleosomes. This is a challenging task for cells because changes in rates of DNA synthesis lead to an accumulation of excess histones, which interfere with many aspects of DNA metabolism. In addition, cells need to ensure that histone variants are incorporated at the correct chromosomal location. Recent discoveries have highlighted the importance of regulated histone proteolysis in preventing both the accumulation of excess histones and the mis-incorporation of histone variants at inappropriate loci.

The emergence of regulated histone proteolysis.

Histones are essential proteins that package the DNA in all eukaryotes into chromosomes. However, histones can accumulate upon a decrease in DNA synthesis that occurs at the end of S-phase or following replication arrest. These positively charged histones can associate non-specifically with the negatively charged DNA and other cellular biomolecules, impairing their normal function. Hence, cells have evolved numerous strategies to limit the generation of excess histones and prevent deleterious effects due to their accumulation. Such strategies for histone regulation are discussed here, with particular emphasis on recent studies that implicate the DNA damage checkpoint kinases in the regulation of histone levels, especially in response to replication inhibition. We have also focused upon the recently discovered regulatory mechanism involving histone proteolysis in the budding yeast. Additionally, we speculate that cells may possess a surveillance mechanism for sensing histone levels, particularly in the G1 and S-phases of the cell cycle. Proper regulation of histone levels has major implications for the maintenance of epigenetic marks on chromatin, genomic stability and the packaging of sperm DNA.

Generation and management of excess histones during the cell cycle.

Social stress has been linked to several neuropsychiatric diseases, including depression, which is a debilitating disease that has genetic, environmental, and epigenetic underpinnings.

The effects of repeated social defeat on long-term depressive-like behavior and short-term histone modifications in the hippocampus in male Sprague-Dawley rats.

Although keloids have been empirically treated with steroids and radiation, evidence-based radiation parameters for keloid therapy are lacking.

Treatment of keloids with a single dose of low-energy superficial X-ray radiation to prevent recurrence after surgical excision: An in vitro and in vivo study.

Article	Year
The emergence of regulated histone proteolysis. Current opinion in genetics & development\| PubMed ID: 16510276	2006
Generation and management of excess histones during the cell cycle. Frontiers in bioscience (Landmark edition)\| PubMed ID: 19273263	2009
The effects of repeated social defeat on long-term depressive-like behavior and short-term histone modifications in the hippocampus in male Sprague-Dawley rats. Psychopharmacology\| PubMed ID: 20454892	2010
Treatment of keloids with a single dose of low-energy superficial X-ray radiation to prevent recurrence after surgical excision: An in vitro and in vivo study. Journal of the American Academy of Dermatology\| PubMed ID: 32540415	2020

Akash Gunjan

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